Typical subsea drilling operations include a variety of components at or near the seabed. Such components include a lower stack, including blowout preventer (BOP) rams, as well as a lower marine riser package (LMRP) typically attached to the lower stack. The LMRP typically includes control pods, sometimes referred to in the industry as blue pods and yellow pods. These pods control the functions of the subsea components and communicate with an operator at the sea surface via a multiplex (MUX) cable or umbilical. The MUX or umbilical provides power and communications ability, among other things, to the control pods.
In addition to the electrical MUX cable, hydraulic lines providing the hydraulic utility to the subsea valves are also routed to the BOP. At a vessel or platform on the sea surface, MUX cables and hydraulic lines typically store on reels, which are configured to wind or unwind the MUX cables and hydraulic lines into the sea so it run to the subsea control pods. Such reels are complex, and include, for example, drive motors, level winds, brakes, and other components that must be controlled and monitored.
In certain systems, the control of a reel is either locally at the reel, or remotely, via a pneumatic console. The valves on the pneumatic console send pneumatic signals to a reel assembly, thus allowing control of the reel drive system and ultimately managing the spooling in/out of the MUX cable, umbilicals, and hydraulic lines. Although the console may allow for remote control of a reel, it is fully pneumatic.